The Hypogeum, is a labyrinthine complex of man-made chambers carved out of limestone that goes underground for approx 11 meters. Experts believe it was used as a burial site and temple by Neolithic man, who used antlers and stone picks to carve out the labyrinth in semi-darkness nearly 5,000 years ago. The site has been declared a UNESCO World Heritage site. Archaeologists have recovered numerous statues, amulets, figurines and vases, many of which are on display in the Archeology Museum in Valletta.